When she heard the question she can't help but give a soft smile," Yes, riding on swords. Those with strong spiritual energy can use that energy to fly on swords." She, herself, didn't have the spiritual energy that her baby brother had but she hadn't truly cultivated for as long as he had. Just as her other brother would no longer ever use spiritual energy again, not after his fall.
"I have never seen such a thing within a movie." Then again... movies were rather new to her. So she can't say she's seen the same things that George has seen. Just as she wouldn't be able to say what kung fu was either. Though she was familiar with martial arts, but more with the Jiang fighting style than anything else.
When she's asked if she wanted to try it, though, she stares at the board then looks toward George," Is it safe?" How much spiritual energy and strength did one need for such a thing?